A handkerchief that a regular visitor to Nacrene City's Cafe Warehouse dropped. Faintly smells of Pokémon.
The Dirty Handkerchief is a key item introduced in Generation V which is given by a person inside the Nacrene City café. Upon being given, the player is given the task of returning the handkerchief. When you return it the user (of the hankerchief) will thank you. When you report to the person who gave you the job of returning it, she will give you a fluffy tail.